What is usas national anthem?

The Star-Spangled Banner is the national anthem of the United States of America. The lyrics come from a poem titled "Defence of Fort M'Henry", that Francis Scott Key wrote after witnessing the bombardment of Fort McHenry by British ships in Baltimore Harbor during the Battle of Baltimore in the War of 1812. Although there were other American patriotic songs at the time, The Star-Spangled Banner was not recognized as the national anthem until 1931.